1 /* 2 * Copyright 2016 Intel Corp. 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 21 * OTHER DEALINGS IN THE SOFTWARE. 22 */ 23 24 #ifndef _DRM_VBLANK_H_ 25 #define _DRM_VBLANK_H_ 26 27 #include <linux/seqlock.h> 28 #include <linux/idr.h> 29 #include <linux/poll.h> 30 31 #include <drm/drm_file.h> 32 #include <drm/drm_modes.h> 33 34 struct drm_device; 35 struct drm_crtc; 36 37 /** 38 * struct drm_pending_vblank_event - pending vblank event tracking 39 */ 40 struct drm_pending_vblank_event { 41 /** 42 * @base: Base structure for tracking pending DRM events. 43 */ 44 struct drm_pending_event base; 45 /** 46 * @pipe: drm_crtc_index() of the &drm_crtc this event is for. 47 */ 48 unsigned int pipe; 49 /** 50 * @sequence: frame event should be triggered at 51 */ 52 u64 sequence; 53 /** 54 * @event: Actual event which will be sent to userspace. 55 */ 56 union { 57 /** 58 * @event.base: DRM event base class. 59 */ 60 struct drm_event base; 61 62 /** 63 * @event.vbl: 64 * 65 * Event payload for vblank events, requested through 66 * either the MODE_PAGE_FLIP or MODE_ATOMIC IOCTL. Also 67 * generated by the legacy WAIT_VBLANK IOCTL, but new userspace 68 * should use MODE_QUEUE_SEQUENCE and &event.seq instead. 69 */ 70 struct drm_event_vblank vbl; 71 72 /** 73 * @event.seq: Event payload for the MODE_QUEUEU_SEQUENCE IOCTL. 74 */ 75 struct drm_event_crtc_sequence seq; 76 } event; 77 }; 78 79 /** 80 * struct drm_vblank_crtc - vblank tracking for a CRTC 81 * 82 * This structure tracks the vblank state for one CRTC. 83 * 84 * Note that for historical reasons - the vblank handling code is still shared 85 * with legacy/non-kms drivers - this is a free-standing structure not directly 86 * connected to &struct drm_crtc. But all public interface functions are taking 87 * a &struct drm_crtc to hide this implementation detail. 88 */ 89 struct drm_vblank_crtc { 90 /** 91 * @dev: Pointer to the &drm_device. 92 */ 93 struct drm_device *dev; 94 /** 95 * @queue: Wait queue for vblank waiters. 96 */ 97 wait_queue_head_t queue; 98 /** 99 * @disable_timer: Disable timer for the delayed vblank disabling 100 * hysteresis logic. Vblank disabling is controlled through the 101 * drm_vblank_offdelay module option and the setting of the 102 * &drm_device.max_vblank_count value. 103 */ 104 struct timer_list disable_timer; 105 106 /** 107 * @seqlock: Protect vblank count and time. 108 */ 109 seqlock_t seqlock; 110 111 /** 112 * @count: Current software vblank counter. 113 */ 114 u64 count; 115 /** 116 * @time: Vblank timestamp corresponding to @count. 117 */ 118 ktime_t time; 119 120 /** 121 * @refcount: Number of users/waiters of the vblank interrupt. Only when 122 * this refcount reaches 0 can the hardware interrupt be disabled using 123 * @disable_timer. 124 */ 125 atomic_t refcount; 126 /** 127 * @last: Protected by &drm_device.vbl_lock, used for wraparound handling. 128 */ 129 u32 last; 130 /** 131 * @max_vblank_count: 132 * 133 * Maximum value of the vblank registers for this crtc. This value +1 134 * will result in a wrap-around of the vblank register. It is used 135 * by the vblank core to handle wrap-arounds. 136 * 137 * If set to zero the vblank core will try to guess the elapsed vblanks 138 * between times when the vblank interrupt is disabled through 139 * high-precision timestamps. That approach is suffering from small 140 * races and imprecision over longer time periods, hence exposing a 141 * hardware vblank counter is always recommended. 142 * 143 * This is the runtime configurable per-crtc maximum set through 144 * drm_crtc_set_max_vblank_count(). If this is used the driver 145 * must leave the device wide &drm_device.max_vblank_count at zero. 146 * 147 * If non-zero, &drm_crtc_funcs.get_vblank_counter must be set. 148 */ 149 u32 max_vblank_count; 150 /** 151 * @inmodeset: Tracks whether the vblank is disabled due to a modeset. 152 * For legacy driver bit 2 additionally tracks whether an additional 153 * temporary vblank reference has been acquired to paper over the 154 * hardware counter resetting/jumping. KMS drivers should instead just 155 * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly 156 * save and restore the vblank count. 157 */ 158 unsigned int inmodeset; 159 /** 160 * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this 161 * structure. 162 */ 163 unsigned int pipe; 164 /** 165 * @framedur_ns: Frame/Field duration in ns, used by 166 * drm_calc_vbltimestamp_from_scanoutpos() and computed by 167 * drm_calc_timestamping_constants(). 168 */ 169 int framedur_ns; 170 /** 171 * @linedur_ns: Line duration in ns, used by 172 * drm_calc_vbltimestamp_from_scanoutpos() and computed by 173 * drm_calc_timestamping_constants(). 174 */ 175 int linedur_ns; 176 177 /** 178 * @hwmode: 179 * 180 * Cache of the current hardware display mode. Only valid when @enabled 181 * is set. This is used by helpers like 182 * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the 183 * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, 184 * because that one is really hard to get from interrupt context. 185 */ 186 struct drm_display_mode hwmode; 187 188 /** 189 * @enabled: Tracks the enabling state of the corresponding &drm_crtc to 190 * avoid double-disabling and hence corrupting saved state. Needed by 191 * drivers not using atomic KMS, since those might go through their CRTC 192 * disabling functions multiple times. 193 */ 194 bool enabled; 195 }; 196 197 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs); 198 u64 drm_crtc_vblank_count(struct drm_crtc *crtc); 199 u64 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc, 200 ktime_t *vblanktime); 201 void drm_crtc_send_vblank_event(struct drm_crtc *crtc, 202 struct drm_pending_vblank_event *e); 203 void drm_crtc_arm_vblank_event(struct drm_crtc *crtc, 204 struct drm_pending_vblank_event *e); 205 void drm_vblank_set_event(struct drm_pending_vblank_event *e, 206 u64 *seq, 207 ktime_t *now); 208 bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe); 209 bool drm_crtc_handle_vblank(struct drm_crtc *crtc); 210 int drm_crtc_vblank_get(struct drm_crtc *crtc); 211 void drm_crtc_vblank_put(struct drm_crtc *crtc); 212 void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe); 213 void drm_crtc_wait_one_vblank(struct drm_crtc *crtc); 214 void drm_crtc_vblank_off(struct drm_crtc *crtc); 215 void drm_crtc_vblank_reset(struct drm_crtc *crtc); 216 void drm_crtc_vblank_on(struct drm_crtc *crtc); 217 u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc); 218 void drm_vblank_restore(struct drm_device *dev, unsigned int pipe); 219 void drm_crtc_vblank_restore(struct drm_crtc *crtc); 220 221 bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, 222 unsigned int pipe, int *max_error, 223 ktime_t *vblank_time, 224 bool in_vblank_irq); 225 void drm_calc_timestamping_constants(struct drm_crtc *crtc, 226 const struct drm_display_mode *mode); 227 wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); 228 void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, 229 u32 max_vblank_count); 230 #endif 231